If there is a chance to choose the batteries which are genuinely maintenance free, go for it, and I could guarantee, you are 'going to sleep much better'.
A technical guy from Arizona suggested 'Concorde SunXtender Batteries'.
These are completely sealed, genuinely maintenance free, Deep Cycle batteries. They use the Absorbed Glass Mat Technology. They are tough, nearly indestructible. He uses them in his portable solar systems. He also suggests them for an option of 'backup battery bank', to which the excess power/electricity could be directed, when the primary one is topped off.
A deep cycle battery is designed to provide a steady amount of current over a long period of time. It can provide a surge when needed. It is also designed to be deeply discharged over and over again.
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